1. Field of the Invention
The present invention relates to a method for preparing germinated brown rice having improved texture, cookability without microbial contamination and to a germinated brown rice obtained therefrom. More specifically, the present invention relates to a method for preparing germinated brown rice that has better texture, is easier to cook at homes and has higher safety from microbial contamination compared with conventional germinated brown rice, by controlling the conditions for the germination process, and to a germinated brown rice obtained therefrom.
2. Discussion of Related Art
The structure of brown rice consists, from the topmost layer, of the rice bran layer that comprises three layers such as pericarp, testa and aleurone layer, and the embryo occupying a small portion of the base of the rice grain, and the endosperm occupying most of the remaining part. This endosperm, which is filled dominantly with starch, is the edible rice portion.
Compared with milled rice, unpolished brown rice is stable in storage and less susceptible of being damaged by insects or microbes, and does not lose in much nutrients. Therefore, it is rich in fats, proteins, vitamins B1 and B2 compared with milled rice, and does not undergo reduction in the quantity owing to processing. However, in spite of these benefits aspects of brown rice, it is not widely popular because it is less tasty than milled rice, its nutritious ingredients are not sufficiently digested and assimilated, and it is not easy to cook. Consequently, germinated brown rice is drawing more interest.
Germinated brown rice results from germination of the embryo of brown rice through various physiological changes within the rice grain under conditions suitable for germination. Compared with conventional brown rice, germinated brown rice is effectively digested and assimilated in the body, and it is recognized as a functional food with high contents of nutrients beneficial to the human body, such as γ-aminobutyric acid (referred to as GABA), ferulic acid, diet fiber and the like.
However, germinated brown rice has problems of producing offensive fermentation smell and bad odor during the germination process because of the metabolism of brown rice itself as well as the growth of microbes that are attached to the surface of the grain, and undergoing putrefaction during the germination process. Thus, these problems occurring in the germination process should be avoided for the preparation of high quality germinated brown rice. The aforementioned problems should be necessarily recognized in order to satisfy the demand of consumers, and in fact quality control of germinated brown rice through controlling various conditions in the process for preparing germinated brown rice is required.
According to the results of many researches on germinated brown rice, it is reported that as brown rice undergoes germination, its texture becomes soft to a certain extent owing to the physiological activity of brown rice itself and activities of various enzymes, and thereby preparation of a rice which is very easy to cook and has soft texture, compared with normal brown rice, is possible. However, practically there is limit in overcoming such dissatisfaction on conventional brown rice only by adopting the germination process, and the product quality is much too low to satisfy the fastidious demand of consumers. Thus, techniques such as follows are being introduced as a result of researches to improve various properties of brown rice (e.g., texture, cookability, etc.).
Korean Patent No. 247686 discloses a method for making germinated brown rice wherein rice grains still covered with the husks are immersed in brine to sort out those grains with high germinating potential, and then these selected rice grains are partially polished to brown rice, which are subjected to processes of germinating in water and germinating in air repeatedly.
Korean Patent Publication No. 2000-37091 describes a germinating apparatus for repeating the germination process comprising the steps of washing brown rice while circulating water in the germination bath, germinating brown rice in water, discharging water from the germination bath regularly while germination, and injecting air into the bath by an air injection motor.
Korean Patent Publication No. 2002-71208 discloses a device for drying germinated brown rice rapidly to a water content of 25 to 42%, and a method for drying and packaging germinated brown rice comprising the step of drying of germinated brown rice followed by heat treatment. This patent discloses data on the improvement of the cookability of brown rice at homes.
Korean Utility Model Publication No. 2000-07517 discloses an electric heater for the preparation of edible germinated brown rice, which is used to cook brown rice.
Korean Patent Publication No. 2001-111002 discloses a method for preparing germinated brown rice having good cookability, texture and preserving property, wherein germinated brown rice prepared by controlling the water content, degree of gelatinization and the efficiency of water absorption during immersion in water, is subjected to steaming or moist heating, followed by drying.
However, in spite of aforementioned various techniques, there has been a continued desire to improve the quality of the geminated brown rice because the techniques could not resolve completely the problems such as the prolonged process of germination, prolonged cooking and inconvenience in cooking, the rough texture and abnormal odor of brown rice remained after cooking.
In this regard, the inventors of the present invention have conducted researches to solve the technical problems in quality and preparation process that conventional germinated brown rice products have and to develop a high-quality germinated brown rice which has high safety against microbial contamination, highly nutritious, and easy to cook at homes, and found that the texture of germinated brown rice can be improved by lightly grinding brown rice to partially remove its outermost skin, putrefaction of germinated brown rice can be prevented and its abnormal odor can be removed through controlling appropriately the germination conditions such as pH and temperature of the germination water, air injection, change interval of the germination water and so on, and treatment of germinated brown rice under high temperature and high pressure can lead to the improvement of the safety against microbial contamination and cookability as well as further improvement of the texture of brown rice.
Therefore, the object of the present invention is to provide a method for preparing germinated brown rice that has high safety against microbial contamination, highly nutritious, easy to cook at homes and soft in texture after cooking.
Another object of the invention is to provide a germinated brown rice prepared by the method according to the present invention.